RESUMO
OBJECTIVE@#To investigate the efficacy of a novel artificial perfusate based on oxygen-carrying perfluoronaphthalene-albumin nanoparticles in normothermic machine perfusion (NMP) for preservation of porcine liver donation after cardiac death.@*METHODS@#Artificial perfusate with perfluoronaphthalene-albumin nanoparticles was prepared at 5% albumin (w/v) and its oxygen carrying capacity was calculated. The livers of 16 Landrace pigs were isolated after 1 h of warm ischemia, and then they were divided into 4 groups and preserved continuously for 24 h with different preservation methods: cold preservation with UW solution (SCS group), NMP preservation by whole blood (blood NMP group), NMP preservation by artificial perfusate without nanoparticles (non-nanoparticles NMP group) and NMP preservation by artificial perfusate containing nanoparticles (nanoparticles NMP group). Hemodynamics, tissue metabolism, biochemical indices of perfusate and bile were monitored every 4 h after the beginning of NMP. Liver tissue samples were collected for histological examination (HE and TUNEL staining) before preservation, 12 h and 24 h after preservation.@*RESULTS@#The oxygen carrying capacity of nanoparticles in 100 mL artificial perfusate was 6.94 μL/mmHg (1 mmHg=0.133 kPa). The hepatic artery and portal vein resistance of nanoparticles NMP group and blood NMP group remained stable during perfusion, and the vascular resistance of nanoparticles NMP group was lower than that of blood NMP group. The concentration of lactic acid in the perfusate decreased to the normal range within 8 h in both nanoparticles NMP group and blood NMP group. There were no significant differences in accumulated bile production, alanine aminotransferase and aspartate aminotransferase in perfusate between nanoparticles NMP group and blood NMP group (all P>0.05). After 24 h perfusion, the histological Suzuki score in blood NMP group and nanoparticles NMP group was lower than that in SCS group and non-nanoparticles NMP group (all P<0.05), and the quantities of TUNEL staining positive cells in blood NMP group and non-nanoparticles NMP group was higher than those in nanoparticles NMP group and SCS group 12 h and 24 h after preservation (all P<0.05).@*CONCLUSION@#Artificial perfusate based on oxygen-carrying nanoparticles can meet the oxygen supply requirements of porcine livers donation after cardiac death during NMP preservation, and it may has superiorities in improving tissue microcirculation and alleviating ischemia-reperfusion injury.
Assuntos
Animais , Suínos , Transplante de Fígado , Preservação de Órgãos , Fígado , Perfusão , Morte , Oxigênio/metabolismoRESUMO
BACKGROUND: Acute gastrointestinal injury is associated with significantly increased mortality in critically ill patients. However, markers for measuring acute gastrointestinal injury are neither sensitive nor specific. OBJECTIVE: To determine whether enzymes in digestive fluid are predictive of the severity of acute gastrointestinal injury. METHODS: A prospective observational study was conducted between June 2015 and December 2015 in a surgical intensive care unit. Enrolled patients were classified by acute gastrointestinal injury grade according to the 2012 European Society of Intensive Care Medicine system. Digestive fluid was collected through nasointestinal tubes and analyzed 24 hours after the diagnosis of acute gastrointestinal injury. Intestinal markers of injury (pH, interleukin 6, interleukin 10, tumor necrosis factor α, and secretory immunoglobulin A) were measured in digestive fluid. RESULTS: Of the 76 patients included, acute gastrointestinal injury was grade I in 41, grade II in 20, grade III in 8, and grade IV in 7. Secretory immunoglobulin A was an independent predictor of grade III acute gastrointestinal injury. When data from patients with grades I and II injury and patients with grades III and IV injury were grouped together, analysis revealed that pH, interleukin 10, and secretory immunoglobulin A were independent predictors of acute gastrointestinal failure. CONCLUSIONS: Secretory immunoglobulin A was predictive of grade III acute gastrointestinal injury. Digestive fluid markers of injury (pH, interleukin 10, and secretory immunoglobulin A) were predictors of acute gastrointestinal failure. Further study is required to determine if other markers are specific or sensitive for acute gastrointestinal injury.
